Lathe-chuck jaw



( o Model.)

J. N. SK INNER LATHE CHUCK JAW.

No. 463,373. PatentediNov. 17,1891.

NITE TATES JAMES N. SKINNER, OF NE\V BRITAIN, CONNECTICU".

LATH E-CH UCK JAW.

SPECIFICATION forming part'of Letters Patent No. 463,373, dated November 17, 1891.

Application filed June 30, 1891. Serial No. 398,022. (No model.)

To ctZZ whom, it may concern.-

Be it known that 1, JAMES N. SKINNER, of New Britain, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Lathe-Chuck Jaws, of which the following is a full, clear, and exact description,wherebyany one skilled in the art can make and use the same.

The object of my invention is to provide a chuck-jaw that is particularly-intended for use in lathe-chucks that have a reversible section that is capable of easy adjustment and is of simple and cheap construction and capable of .being made by the use of the ordinary machine-tools.

To this end my invention consists in details of the several parts making up the chuckjaw as a whole and in their combination, as more particularly hereinafter described, and pointed out in the claims.

Referring to the drawings, Figure 1 is a detail side view of a chuck-j aw embodying my improvement. Fig. 2 is a detail plan view of the lower section. Fig. 3 is a detail View in the central vertical section of the jaw with 'the upper section in a reversed position to that shown in Fig 1 of the drawings. Fig. 4 is a detail view, on enlarged scale, in crosssection through the dowel-socket in the two jaw-sections, showing the modified form of the dowel.

In the accompanying drawings, the letter (t denotes the lower or main section of the chuck-jaw, and I) the reversible section, the two sections preferably having flat meeting faces at the plane of partition between the two sections. The sections are secured together by screws 0 and d, that extend through holes in the upper section into threaded sockets c d in the lower section. In the meeting faces of these two sections shallow recesses, forming sockets e e and f f", are made these sockets in the opposing faces registering with each other, so that a removable dowel 9 will extend as to part of its length into the opposing sockets in the respective parts of the jaw-sections. These dowels and the inclosing sockets are preferably arranged so that the fastening-screws extend through the sockets and through the dowels; but this precise location is not essential.

In Fig. 2 circular annular dowels located in sockets surrounding screw-sockets are I shown; but any other convenient form of dowel as to shape and cross-section may be used so long as the dowel may be readily removed and renewed or turned a part of the way around so as to present new holdingedges in the socket.

' In the use of a chuck-jaw'made in accordance with my invention the strain that tends to slide the two sections lengthwise upon each other when the jaw is in use in holding a piece of work causes a shearing strain to to be brought upon the dowels. This strain is liable to wear the dowels on the sides toward which the strain tends to move the parts. Such wear can be taken up by removing the upper section and turning the dowel in its socket until new parts are presented, or, if need be, the socket may be reamed out slightly larger and a new dowel inserted, thus greatly increasing the durability of, the reversible jaw. If it is desired, the dowel shall remain in one of the two sockets. This may be accomplished by slightly tapering the dowel on one side and leaving it free as to the other side, so that it will fit snugly into the sockets in one section and not so tightly in the socket in the opposing section. By slightly tapering the dowels I am also able to provide for an adjustment to take up the wear that is accomplished by cutting oif slightly from the narrower end of the dowel,

thus enabling it to be set a little deeper in the socket. By means of this improvement the shearing strain is in large part taken off the fastening-screws and borne by the clowels, and I am also enabled to make an extension-jaw by arranging the dowel-sockets and dowels so that the upper section of the jaw may be set over so as to overhang the lower section of the outer end, the dowels affording a sufficient support to stand the shearing strain and the screws servingto hold the parts together.

The meeting faces of the jaw-sections may be finished by a series of straight cuts in any suitable machinctool, and the sockets are made by boring. The meeting faces between the parts may be hardened and then ground to a perfect fit, due to the fact that they are flat surfaces.

The dowels may be cheaply made to aproper size and suitably hardened by extremely cheap methods, and they may be made interchangeable in several sizes of the sections, and removable dowels located in sockets formed in the meeting faces of the two sections, all substantially as described.

3. In a chuck-jaw, in combination with a main section, a reversible section, fasteningscrews extending between the jaw-sections, annular sockets surrounding the screw-holes and opening toward the meeting faces of each jaw-section, and annular removable dowels tapered toward one end, all substantially as described.

JAMES N. SKINNER.

lVitn esses:

W. B. JENKINS, CHAS. L. BURDETT. 

